1. Field of the Invention
The present invention relates to a display device driving method that saves power by placing in a display state only the pixels corresponding to the intersection of particular scanning lines and particular data lines, while placing in a non-display state all other pixels. The present invention also relates to a driving circuit for driving the display device, display device and electronic equipment.
2. Description of Related Art
The number of display dots on display devices used in mobile electronic equipment such as mobile telephones is increasing year by year in order to enable these devices to display more information. On the other hand, mobile electronic equipment must have low power requirements, since they are typically battery operated. For this reason, display devices used in mobile electronic equipment require two seemingly contradictory characteristics: high resolution and low power consumption.
To resolve this problem, a driving method called partial display driving (also simply referred to as partial driving) has been proposed. Partial display driving here refers to a method of generating a display such as that shown in FIG. 31 when a full screen display is deemed unnecessary, such as during standby mode. Specifically, only particular scanning lines are supplied with a scanning signal so that pixels at intersections of the particular scanning lines and the particular data lines are set to work as a display area while the remaining pixels are set to be in a non-display state, thus reducing the consumption of power.
In such a partial display driving method, the scanning lines other than the particular scanning lines (the scanning lines in the non-display area) are supplied with a voltage equal to the intermediate voltage of a data signal supplied to the data line, but since the intermediate voltage needs to be separately generated, and since a circuit driving the scanning lines needs to select the voltage equal to the intermediate voltage, the circuit arrangement for driving the scanning lines becomes complex.
In addition, with such partial display driving, even if only several characters are displayed in the display region, a pixel that is in an area outside the character display and that is located on the same row on which the characters are displayed is included in the display area even though it does not display a character. In a structure in which pixels are simply supplied with a non-lighting voltage through a data line, the frequency with which voltage applied to the data line is switched (switching frequency) is not reduced. Therefore, reducing the power consumption is surprisingly difficult.